Lasers have been used in, for example, urology, neurology, otorhinolaryngology, general anesthetic ophthalmology, dentistry, gastroenterology, cardiology, gynecology, thoracic, and orthopedic procedures. More specifically, these procedures may entail the delivery of laser energy as part of treatment protocols. One example of a procedure that may be performed using a laser is lithotripsy. Lithotripsy involves treating a subject's kidneys, ureters, or bladder by removing material therein, such as calculi or stones. Laser lithotripsy is a subset of lithotripsy where laser energy is applied to break down the material, thereby facilitating removal of the material. In one exemplary laser lithotripsy procedure, a laser fiber may be inserted through the working channel of an introducer, such as an endoscope, to the targeted material. The laser fiber may emit laser energy at the targeted material to break down the targeted material into pieces. The pieces may be washed out of, or otherwise removed from, the subject.
The laser fiber may be placed in contact with, or nearly in contact with, the targeted material prior to the application of the laser energy. The targeted material may, in some instances, be in contact with water. Since the water also may absorb the laser energy, the water may be affected by the laser energy intended for the targeted material. For example, the laser energy absorbed by the water may produce shockwaves in the water. The shockwaves may damage the laser fiber. Such damage may reduce the amount of laser energy emitted from the laser fiber. Fixing the damage by, for example, cleaving the damaged portion of the laser fiber, and then re-inserting the laser fiber into subject to continue with a procedure, may increase the time and cost associated with performing the procedure.
Another challenge associated with laser lithotripsy is that differently sized laser fibers may be used, with the laser fiber size being selected based on the location of the targeted material in the subject. For example, a laser fiber having a smaller core size may be selected to reach material in a subject's lower kidney pole. One reason for this selection is that the laser fiber with the smaller core size may be bent to form a tighter curve than an laser fiber having a larger core size, making it easier to maneuver the laser fiber with the smaller core size into the target area. The laser fiber having the smaller core size may, however, be used with the same laser generator as the laser fiber having the larger core size. If the core size of the laser fiber is smaller than that of focused laser energy generated by the laser generator, and/or if the focused laser energy delivered from the laser generator to the core is misaligned or greater than the optical fiber's acceptance angle, errant laser energy may be transferred to components outside of the core, possibly damaging those components and negatively impacting the performance of the laser fiber.
Solutions that can deliver laser energy to targeted material, while reducing or eliminating the occurrence of the above-described drawbacks, may lead to better outcomes for users and subjects.